Table 7.

Improper torsion potential functions and their parameters (fifth section of data scheme, cf. Figure 5), where Ψ is the out of the plane angle formed by the interaction sites under consideration and l are potential parameters.

ID5	function	p1	p2
1	$l_2\frac{{\left(\mathrm{\Psi }{-\mathrm{\Psi }}_0\right)}^2}{2}$	l2	Ψ